Propulsion of vessels



April 1 1924;

6 Sheets-Sheet 1 D. V. HOTCHKISS PROPULSION OF VESSELS Filed July 10 nll llllll April 1 D. HOTCHKISS PROPULS ION OF VESSELS Filed July 10 1920 6 Sheets-Sheet 2 April- 1 1924. 1,489,079 D. V. HQTCHKISS PROPULSION OF VESSELS Filed July 10 1920 6 Sheets-Sheet 5 April 1 1924..

D. V. HOTCHKISS PROPULSION OF-.VESSELS Filed July 10 1920 6 Sheets-Sheet 4 April 1, 1924. 1,489,079

D. v. HOTCHKISS PROPULSION OF VESSELS Filed July 10 1920 s Sheets-Sheet s April 1 1924.

D. v. HOTCHKISS PROPULSION OF VESSELS Filed July 10 1920 6 Sheets-Sheet 6 Patented Apr. 1, 1924. I

UNITED STATES PATEN DONALD VIVIAN HOTCHKISS, or HELENSIBURGH, soo'rmm, 'ASSIGNOR TO THE.

r OFFICE.

HOTCHKISS HYDRAULIC PROPELLER COMPANY, LIMITED, 01? LONDON, ENGLAND.

PROPULSION OF VESSELS.

Application filed July 10,

To all w/mm it may concern: Be it known that I. DONALD VIvIA'N Ho'rcHmss, ot' (ireen Point Cottage, Princes.

= Street, Hclensburgh, Scotland. a subject of the vKing of (ireat Britain, have invented certain new and useful Improvements in the' Propulsion of Vessels, of' which thefollowmg i a specification.

This invention relates to the fluid propul-' sion of ships, aircraft and the like.

Fluid propellers have already been proposed for the propulsion of. ships but these have not proved satisfactory mainly because.

of the high frictional losses set up due to the formation of eddy currents. and to the conversion by centrifugal action of velocity head into pressure head.

The object of the present invention is tov provide an improved.method of and means for the fluid propulsion of ships, aircraft and the like whereby such losses will be reduced to a minimum. A further object is to provide a fluid propeller specially a apted for use in vcsselsintendcd for service in shallow or weedy waters.

To the attainment of these objects tlie invention consists primarily in propelling the vessel by the actionsof an induction vortex which, when the vessel is in motion, is fed by streams of fluid entering only in the dircction of rotation at the sides and between the centre and circumference of the vortex, the streams being caused to merge finally into a single stream discharged tangentially at the circumference. By the term vortex as herein used I mean a-gyrating mass of fluid the particles of which, in a single circuil. pass from orbits of less to orbits of greater diameter, acceleration of the fluid taking place gradually during the circuit from entry to discharge.

The invention further consists of a fluid propeller comprising a casing, preferably elliptical in cross section, and an impeller mounted for rotation therein said casing having inlet openings in the opposite. sides disposed between the centre and the circumference and also having at least one tangem tial discharge opening in the pe ipheral wall in the same radial plane as said inlet openings, whereby, when the propeller is fitted in.the bottom of a vessel with the inlet and discharge openings exposed to the surround- 1920. Serial no. 395,224.

substantially as herein described with refer-.

once to the accompanying drawings and pointed out in the'appended claims.

.In order that the invention may be clearly understood explanatory drawings are hereunto appended whereon two constructions of the propelling apparatus stlitable for water craft are shown byway ofcxample.

Fig; 1 is a diagram illustrating the action of the, apparatus.

F ig. 1 is a longitudinal section showing an hydraulic propelling apparatus fitted in the shell of a ship at the bottom thereof.

Fig. 2 is an inverted plan view of the apparatus, Fig.1.

' Fig. 3 shows a pair of hydraulic propellers as fitted in the ship one on each side of the keel. Fig. 4. is a view of the apparatus, Fig. 1, but arranged so as togivea reverse drive.

Fig. 5 i a. view of an adaptation of the hydraulic propellingapparatus suitable for small craft. such as motor boats or the like. he apparatus is shown in longitudinal sec tion.

Fig. 6 is a vertical cross section on line 6(S, of Fig. 5.

4 Fig. 7 is a sectional plan on line 7-7, of

Fig. 8.is a view of the impeller. I

()n the drawings the same reference letters wherever repeated indicate the same or similar parts. p 1

Referring first to Fig. I, it will be seen that adrum B constructed of any suitable material impervious to chemical action from the fluid concerned, is provided. This drum. which may be of rectangular or preferably slightly elliptical cross section, is provided with means, such as a paddle wheel or impeller A, by the aid of which a vortex may be formed and maintained having the same axis as that of the drum.

A single segment, including a portion of to leave an o enin iii drum, is removed so as C which forms both the inlet and'out et. E. are the two inflowing or feeding streams of fluid and F the the periphery of the 'outflowing or discharge stream which, in

sectionpappears as at F. The impeller is rotated in thedirection of the arrows 00,11 In the arrangement preferred the drum 1s installed in the ,ship so that the portion containing this opening projects through the sides or bottom of the hull the fluid being caused to flow into the drum at a point between the periphery, and the centre, and not at a point nearer the periphery both entrance and delivery being in the horizontal plane, or substantially so. The drum may be iven any convenient proportions suitable to t e ship it is desired to propel, the greatest breadth consistent with eflicient operation being about equal to the diameter and the most generally eflicient proportions being found when the breadth is equal to half the diameter.

In order to encourage the flow of fluid into thedrum when the ship is at high speed, and at the same time to reduce the head resistance offered to forward motion b the portion of the drum projecting outsi e the ships hull,'a stream line body is provided. This is arranged so that the region of posi- I .tive pressure at the quarters is coincidentwith the portion of the opening inthe drum forming the intake. Thefluid, therefore, is induced to enter'the intake portion of the opening b means which are supplementary to the action of the vorteii.

The fluid, entering the drum, performsf a I double function, (a) to supply and feed the vortex so as to maintain a constant discharge, (b) to separate the outgoing or discharge stream from the rotating mass. ,It is to enable this latter. function to take place naturally that the opening-is made largein area I so that this. action-which is a natural one,

may take place without undue-interference from solid substances to which the fluid has relative, velocity.

The actual sectional entering the drum and also of the discharge stream, are'govern'ed by a balance between the forces at workkin the fluid itself.

zfilInthe construction preferred, the drum is constructed in halves, being split {thorirmoved ,togetheii shaftwithout disturbing the lower "A disc of sm 'le'material other recognised device-[Blades are slotted nto the periphery, the blades making a reasonable clearance withthesides and peareas of the streams.

- the dllvlllg shaft by of,a keyway or riphery of the drum and being set transversely to the plane of the disc, after the manner of floats in a radial paddlejwheel. The blades are preferably curved so as to present a concave face to the direction of rotation, but the may be curved in any manner desired. he blades maybe six in num her or any convenient number may be fitted. When the drum is made elliptical in form,

' the im eller may be constructed as described;

but, i desired, it may be constructed with flat-or slightly curved blades with parallel sides, each blade ,having a parallelwidth,

equal approximately to the width of the opening in the drum at the periphery.

Any convenient number of blades may be employed consistent with structural consideration, four being preferred.

Wheri the shaft is rotated the propeller commences to draw in fluid from the direction ahead of the ship, accelerates it during one orbitof thevortek and discharges it in a rearward direction with increased velocity, the reaction rcsolving'through the impeller, into a. horizontal thrust on the bearings,

driving the ship forward. Direct reversibility is obtainable by reversing thedirection of rotation of the impeller shaft. I

I shall now describe the methods by which theprop'eller may be made reversible whilst the direction of rotatibn of the drivingshaft remains unaltered.- I

To the drum arranged as described is added a tube or duct leading from the portion of the periphery where the direction 'of the rotating fluid is opposite to the'direction of discharge, to the stream linebody described and ending inal'jet or mouthpieceffacing forwards or substantially forwards. ,A second drum or portion of a drum, or shoe,

' is provided which fits concentrically into the first drum and is capable of rotation therein. This inner drum is suspended on trunn'ions projecting outwards from its sides, and means are provided for its rotation through any desiredangle. The inner drum has an opening of larger area than that of the outer drum, so that,when the openings inthe two drums register, that of the inner drum extends around a greater are of the outer drum than is represented by the extent ofthe opening therein. If the inner drum is rotated, during each revolution it out the foIlowingfnnctions:-'

1. The opening in the outerdrum is. unaltered, since the opening in the inner dr'iim registers therewith, the extra extent of the opening in the inner drum being overlapped by the sides of the outer-drwn. The pro-- p'eller, therefore operates, driving the ship by the inner drum. being turned so that this T K s 2. The opening of the outer drum is closed 5 ing of four blades on mounted on the central the prime mover is relieved of any load in portion of the opening in the outer-drum,

reversal therefore takes place through the lluid flowing through the reverse outlet in the ahead direction.

L- \Vhe n the opening in the inner drum registers equally with both the opening of the outer drum and the aster-n opening thereof giving equal reactions in the ahead and astern directions. In this condition, the thrusts being balanced the ship remains stationary with the prime mover under full load.

It will be seen from the foregoing that by rotating the inner drum, any of these conditions, and any condition lying between them, can be obtained, that is to say, that if, for instance. two propellers are fitted, one on either side of the hull and driven by a single shaft rotating in one direction only and at constant speed a full manoeuvring power as in the case of a twin screw installa-v tion, is obtainable.

In special cases in whichshallow draught is of the greatest importance, a recess may be built in the hull and the propeller carried therein. In such case's, reversal may be effected either in the manner described, or by means of a triangular block fitted under the out let of the drum. This block would be arranged so that it could be slid horizontally in such manner as to deflect the outgoing stream from an astern to an ahead direction.

For use in weedy waters fitted over the intake holes be made detachable.

In the construction according to Figs. 1 to 4, a drum 6, constructed of any suitable material is fitted in the bottom a of the vessel; so that, as will be seen, its major grids may be and these may portion is within the vessel whilst its minor,

and under portion, projects below the bottom of the vessel and into the water. The drum has (see Fig. 3) curved sides-and is somewhat elliptical in cross section. In the interior of the drum is an impeller conslstboss Z of the shaft Z which latter is driven in any suitable and convenient manner from a prlme mover Which may be a motor or a steam engine, as found most suitable.

A portion of the periphery of the drum at the underside thereof is removed as shown and 2 soas to leave a gap or opening is. In each-side of the drum is an opening j of somewhat elliptical shape and these lateral openings constitute the Wa-.

7 outlet for the water when the ing to the ter inletsand, as will be seen, they are located between the periphery and the centre of the drum. The opening it: constitutes the vessel is being driven forward. As the impeller revolves water is constantly admitted as two eonverging streams through the lateral open ings j and moving together pass around the interior of the drum, being finally expelled as a single and intermediate stream through the peripheral opening Ir. If so desired the parts 6 (see particularly Fig. 3) separating the openings j from the opening is may be cut away along the dotted lines j, j*, so as to form one ltll'gGCQlll-lllllous opening from side to side. which would serve both as the water inlet and outlet. A stream line body 6 is provided at the underside of the drum at its forward end and likewise a stream line body at its rearward end the stream line bodies being shaped as shown at Figs. 1 and 2.

The drum is preferably provided with strengthening plating fatthe front.

When it is desired that the vessel should be capable of reversal without reversing the prime mover, the front of the drum is provided with a duct 0 having a grid (1 at the mouth thereof which faces forwards as shown at Figs. 1 and 2. As will be seen the curved extension I) of the drum periphery may form the. top of the duct a whilst the correspondingly curved part 0 of the stream line body e may form the bottom of the duct. The curve or sweep of the duct is such as to suit the discharge from the impeller.

In order that a reverse drive can-be given without changing the direction of rotation of the impeller there is mounted concentrically Within the fixed drum 6 a second movable drum h which can turn freely on the bearings 8, 8 the drum being provided with a bevel gear drive (1 rotatable by means of a shaft 1, so that, by turning the shaft by hand or by power, as preferred, the drum can be turned relatively to the fixed drum b more, or less, as desired. The movable drum 72. has a gap 0 in its periphery correspondgap is of the fixed drum and has also in each side thereof, a large opening 71 and 'parts of these openings when the drum is in the position shown at Fig. 1 register with the openings j in the outer drum thereby permitting the water through both drums. It will be seen at Figs.

to pass l'fiand 4; wliilst the openings 7' are somewhat ellipticalin shape the openings 27 whilst partially corresponding to the openings .j are much longer.

When the drum h, is turned to a position so that the'openings 0, whilst the duct 0 is closed as shown at Fig. 1, then the apparatus ,is in position for propelling the vessel ahead, Whereas, when k, and i, j, register, 7

When the drum h is inthepositionshown at Fig. 1 the openings 11, j, serve, as inlets for the water (see arrow 6) whilst the openings o, is, form the outlet for the same the water being ejected astern (see arrow 7) with the result that the vessel is driven forbe driven by separate shafts;

ward: whereas, whenthe drum is turnedto the position shown at Fight-the water enters through the partial openings 2', '7', (see arrow 8) and is ejected through the gap 0 and discharged by the .duct 0 ahead (see arrow 9) with the result that the boat is driven. astern. The mere turning of the drum h is sufiicient without reversing the impeller which continuously revolves in the same direction. I

The impeller shown at Figs. 1 to 4 is of simple construction and consists of four straight blades or paddles m fitted on-the boss Z of the shaft 1..

In many cases it is preferred to have two hydraulic propellers fitted in the vessel and these may at Fig. 3 the two impellers being drivenin conjunction by means of a common shaft Z. If desired however the two impellers may The apparatus as shown at Fi has a single impeller located within the drum 6 fitted centrally at thebottom of thevessel. There are two downwardly inclined intakes n, a, one at each side of the drum these intakes communicating with the inte-' rior of the drum by the inlets t, located between the centre of the drum and its periphcry, and withthe sea' by projecting through the bottom of the vessel forward of the drum. The periphery of the drum has a curved enlargement bwhich forms a dis charge outlet.

In advance and below the drum is a casing m with floor w and opening an therein. The casing is made witha channel which constitutes a discharge outlet 7' and within this channel works a reversing block a. The block is hollow and of-triangular sha e with two curved u er sides a, a and at base which can s11 e alon the floor w. The casing has a curved p ate a) at the end' of the channel this plate corresponding to the side a of the block. The block. can be moved from the position shown in full lines to that shown in-dotted lines and 'vice versa by means of the'lever a links 0 ,1? and pin (v When the block is in the position shown in ,full lines, Fig. 5, the discharge is directed Eastern through the openin 1'. (see arrow 4) "so as to propel the ship orward, whereas, when the block is shifted to the dotted POSI- tion.l. lig, 5, the discharge takes place, (see e arranged in the manner shown Direct use is made of arrow 5) i through the opening an and the able for small craft, the drum 6, has a screw plug w which can be removed when required to give access to the interior of the drum for cleaning or other purpose.

The arrangement shown at Figs. 1 te l gives greater efliciency than that shown at Figs. 5 to 8 as there are no intakes n, n and,

consequently less frictional losses and the rotatable drum also obviates the use of the sliding block. -When the parts 6 are cut away so as to make the same opening serve for both inlet and discharge 1t simplifies the construction.

\It is obvlous the 'h may be substilent if so desired the partial drum or -shoe. being movable within the main drum in the same manner as thedrum h.

.a centrifugal pump, less space is occupied,

and less fluid has to be carried within the 'hull of the ship and losses due to such conversion are eliminated. The savin & piping, as rom the inlet to the impeller and from the impellerito the discharge outlet as in other systems and also the saving of frictional and eddy making losses due to-the use of guide. blades.

ity given to the fluid by the impeller, without any further interference or conversion as in other systems. I i

The incoming streams take substantially the rotational veloc' tuted by a partial drum or shoe or equivaofall frictional losses due tov one change of direction only in becoming part of the vortex obtainingin the drum instead of dividing into spirals in all directions, as in the case of the usual pump with central axial feed.

The whole or part of the apparatus-canbe carried outside the hull of the vessel.

The only conversion from pressure to velocity taking place in my system is brought about gradually by the mixing of the incoming lstreams with the vortex in the drum.

aving now fully described my invention what I claim and desire to secure by Letters Patent is 1. A fluid propeller :comprising a casing and an impeller mounted for rotationin said casing so as to allow free circulation of fluid therein, said casing having inlet open ings disposed, in the opposite side walls between its centre and circumference on one side only of the impeller axis and also having a tangential discharge ppening in its ma ma peripheral wall in the same radial plane as said inlet openings, whereby; upon rotation of the impeller. a fluid vortex is formed in the casing fed by streams of fluid entering in thedirection of rotation of said impeller. through said side inlet openings, the streams finally merging into a single stream discharged tangentially through said discharge opening.

2. A fluid propeller comprising a casing of substantially elliptical cross Ftk'llOll and an impeller mounted for rotation in said casing so as to allow free'circul'ation of fluid therein. tially elliptical inlet openings disposed in the opposite side walls between its centre and circumference on one side only of the impeller axis and also having a tangential discharge opening in its peripheral wall in the same; radial plane as said inlet openings, whereby, upon rotation of the impeller, a fluid vortex is formed inthe casing fed by streams of fluid. entering in the direction of rotation of said impeller through said side inlet openings, the streams finally merging into a single stream discharged tangentially through said discharge opening.

3. A fluid propeller con'iprising a drum having inlet openings disposed in the side walls between its centre-.and circumference on one side only of the; impeller axis and also having two discharge openings in the peripheral wall one of which openings is in the same radial plane as said inlet openings, means for controlling said discharge openings so that when one is opened the other is simultaneously closed, an impeller rotatably mounted in said casing so as to allow free circulation of fluid therein and means for efl'ecting rotation of said impeller.

4. A fluid propeller comprising a drum having inlet openings on one side only of the impeller axis and also having discharge openings in the peripheral wall, a second drum concentrically mounted within the first and havin elongated side openings and also a perlpheral opening, means for turning said inner drum to control said tangential discharge openings in the outer drum, andan impeller mounted for rotation within'said drums so as to allow free circulation of fluid therein.

5. The combination with a-vessel,1o'f a fluidpropeller comprisinga drum fitted in the bottom of the vessel with a part exposed to the fluid medium surrounding the vessel, said drum having fiuidinlet openings in the opposite sides disposed in said exposed part" at a. position between the centre and the circumference and also having a discharge opening in the peripheral Wall in the same radial plane as the inlet openings,

i an impeller mounted within the drum so. as

to allow the fluid free circulation therein said casing having substan-- disposed in the side walls between its centre and circumferenceand means for impeller.

6. The col'nbination with a. vessel of a 'fluid propeller comprising a drum fitted in the bottom of .the vessel witlrits axis horizontal and with a part exposed to the fluid medium surrounding the vessel said drunr having fluid inlet openings in the opposite sides disposed in said exposed part at a posit-ion between the centre and the ci cumference and also having discharge op ings in the peripheralwall one of which is in the same radial plane as the inlet openings, means .for control-ling saiddischarge openings so that when one is opened the other is simultaneously closed, an impeller rotatablv mounted inlthe drum so as to free circulation therein, and means for effecting rotatio n of said impeller;

7. The combination with a vessel of 'a fluid propeller comprising a drum fitted in the bottom of the vessel with a part projecting therebelow; said drum having inlet openings in the opposite sides disposed in said exposed part between the centre and the circumference and also having peripheral discharge openings, a se eflecting. rotation said ,cond drum conallow the fluid centrically mounted within the first, gearing V for turning said inner drum to control said discharge openings and an impeller rotatably mounted in said drums.

8. In a vessel a fluid'propellercomprising an elliptical drum fitted-in the bottom of saidyessel with its medium surrounding the vessel, said drum having inlet openings inthe opposite'side walls located in said exposed part between the centre and the circumference and also having a peripheral discharge opening in said part, intermediate said inlet openings, and an impeller mounted for rotation in said drumso as to allow free circulation of the fluid therein;

9. In a vessel a fluid p opeller comprisin a drum fitted in the bottom of said vesse l with its axis substantially horizontal and with a art exposed to the fluid-medium surroun ing the vessel, said drum havin inlet openings-in the opposite side walls lo-' cated'in said part between the centre and the circumference and also having peripheral discharge openings in-said part one of which is in the same radial plane as the inlet openings, means for controlling said discharge openin sso that when one is 0 en the other is cdosed, an impeller rotata b mounted in the drum and means for rotating said impeller.

10. Means for 'eflecting fluid ropulsion ofa vessel, comprising two similar drums fitted in the bottom of the vessel on opposite sides with parts exposed to the surrounding fluid medium, each of said drums having inlet openings in itsopposite side walls disaxis substantially horizontal and with apartexposed to the fluid tre and the periphery and also having a pe-.

ripheraldiseharge opening in said part, an

impeller rotatably mounted in each drum so as to allow free circulation of fluid thereoperatively connected with a suitable driving source. I

11. Means for effecting fluid propulsion of a vessel, comprising two similar drums fitted in the bottom of the vessel on opposite sides withparts exposed to the surrounding fluid inedium eaoh of said drums-having inlet openings posed insaid exposed part'between' the centre and,

and means whereby said impellercan be circulation of the fiuld therem,

its opposite side walls dis the periphery and also having pe ripheraldischarge openings in said part, an

' turning each inner drum to control the disimpellers rotatably as to allow free and mechanism connecting the impellers with a suitable driving source.

In testimony whereof I aflix my signature charge openings therein, mounted 1n the drums so in presence of two witnesses.

} w I DONALD VIVIAN noroniuss. Witnesses: v E. C. WALKER; J. I. CnAwI-mv. 

